So I decided to to buy a BCM Kino a while back and was kind of dissapointed in the handguard selection. I wanted a Free Float, and to use the standard barrel nut (just cut off Delta ring) and throw one on. I bought a C4 midlength cutout and realized how much I didnt like quad rails anymore. The new slimmer profile rails just feel better. So out the window with using the standard barrel nut. I have Geissele SMR's and they are my favorite. Mk1 and Mk3s to be exact. So I found a MK3 10" and picked one up. The issue with using a 1 piece rail is trying to get the FSB in and pinned with the handguard on. I would assume some rails would just happen to line up perfectly with a hole to pound the pin in straight (KMR?), but the Geissele does not. I looked at the 9.5 inch Mk2 and Mk4 rails but they are too fat for my liking and only cutting off .25 inchs would kinda be funny looking IMO. Mk1 and Mk3 were my only options. So I took a brand new MK3 and took it to the chopping block. I needed to take .75 off the front top 1913 section to give me the proper clearance. The width clearance needed to be right at .82 to allow clearance for the FSB and for the handguard to be able to slightly tilt one way or another to stay level with the upper receiver. Using a mini mill I got it pretty close to my liking. I had to go over a few spots manually after to get it right. The mini mill worked but not like a CNC or other industrial one would. The 45 degree openings on the SMR were the exact width of the 1913 rail on the 12.oclock. So the mills spec was off a few thousands or more so I had to make a few more passes to get it to open the sides up. Its not a professional job by any means, but I would like to think its not a hack either. I just used some flat black high temp paint to touch up the inner machine markings and the front face that mates up to the FSB. I was successful in that I did not mark or destroy any of the external finish. So looking at the handguard from 12, 3, 9, etc, it is all the original finish. The only parts touched up were facing the FSB. The cuts were made vertically, so you would need to look inside the FSB area to see them anyway. The front pin of the FSB was easy to install. The rear pin needed to be shortened. With the handguard tilted as far as it would go (hardly at all) and starting the taper pin in the gas block (with the gas block tilted also) I was able to get it barley started. Rotating the FSB vertical while putting pressure on the pin, let it go into place. There was just enough room to get the edge of the punch on the pin to seat it. The front pin went in afterwards and its good to go. This is just an extra SBR upper at the moment until I decide to get more SBR lowers. Here are two pics I took and only ones I have at the moment.
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Originally Posted by kdcgrohl
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